Prosthetic heart valve devices and methods of valve replacement

ABSTRACT

A stented valve having at least one leaflet made of pericardium or other material having a relatively thin profile at the annulus. The leaflets are attached via chords to a stent frame, where the chords are positioned to mimic the native valve anatomy and functionality. In particular, the valves of one exemplary embodiment of the invention are sized to replace a mitral valve and therefore the chords are arranged to prevent prolapse of the leaflets into the atrium. The stented valve has a relatively short height at its annulus due to the positioning of the chords. In addition, the stented valve is capable of being crimped to a small enough size that it can be delivered to the implantation site via transcatheter delivery systems and methods.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/692,577, filed Dec. 3, 2012, which is a continuation of U.S. patentapplication Ser. No. 12/429,054, filed Apr. 23, 2009, which claims thebenefit of U.S. Provisional Patent Application No. 61/125,235, filedApr. 23, 2008, each of which is incorporated by reference herein intheir entirety.

TECHNICAL FIELD

The present invention relates generally to devices and methods forrepair of heart valves, and more particularly to prosthetic heart valvesfor use in replacement of the mitral valve.

One of the two atrio-ventricular valves in the heart is the mitralvalve, which is located on the left side of the heart and which forms ordefines a valve annulus and valve leaflets. The mitral valve is locatedbetween the left atrium and the left ventricle, and serves to directoxygenated blood from the lungs through the left side of the heart andinto the aorta for distribution to the body. As with other valves of theheart, the mitral valve is a passive structure in that it does notitself expend any energy and does not perform any active contractilefunction.

The mitral valve includes two moveable leaflets that open and close inresponse to differential pressures on either side of the valve. Ideally,the leaflets move apart from each other when the valve is in an openposition, and meet or “coapt” when the valve is in a closed position.However, problems can develop with valves, which can generally beclassified as either stenosis, in which a valve does not open properly,or insufficiency (also called regurgitation), in which a valve does notclose properly. Stenosis and insufficiency may occur concomitantly inthe same valve. The effects of valvular dysfunction vary, with mitralregurgitation or backflow typically having relatively severephysiological consequences to the patient. Regurgitation, along withother abnormalities of the mitral valve, can increase the workloadplaced on the heart. The severity of this increased stress on the heartand the patient, and the heart's ability to adapt to it, determine thetreatment options that are available for a particular patient. In somecases, medication can be sufficient to treat the patient, which is thepreferred option when it is viable; however, in many cases, defectivevalves have to be repaired or completely replaced in order for thepatient to live a normal life.

One situation where repair of a mitral valve is often viable is when thedefects present in the valve are associated with dilation of the valveannulus, which not only prevents competence of the valve but alsoresults in distortion of the normal shape of the valve orifice.Remodeling of the annulus is central to these types of reconstructiveprocedures on the mitral valve. When a mitral valve is repaired, theresult is generally a reduction in the size of the posterior segment ofthe mitral valve annulus. As a part of the mitral valve repair, theinvolved segment of the annulus is diminished (i.e., constricted) sothat the leaflets may coapt correctly on closing, and/or the annulus isstabilized to prevent post-operative dilatation from occurring. Eitherresult is frequently achieved by the implantation of a prosthetic ringor band in the supra annular position. The purpose of the ring or bandis to restrict, remodel and/or support the annulus to correct and/orprevent valvular insufficiency. Such repairs of the valve, whentechnically possible, can produce relatively good long-term results.

However, valve repair is sometimes either impossible or undesirable orhas failed, such as in cases where dilation of the valve annulus is notthe problem, leaving valve replacement as the preferred option forimproving operation of the mitral valve. In cases where the mitral valveis replaced, the two general categories of valves that are available forimplantation are mechanical valves and bioprosthetic or tissue valves.Mechanical valves have been used for many years and encompass a widevariety of designs that accommodate the blood flow requirements of theparticular location where they will be implanted. Although the materialsand design features of these valves are continuously being improved,they do increase the risk of clotting in the blood stream, which canlead to a heart attack or stroke. Thus, mechanical valve recipients musttake anti-coagulant drugs for life to prevent the formation of thrombus.On the other hand, the use of tissue valves provide the advantage of notrequiring anti-coagulant drugs, although they do not typically last aslong as a mechanical valve. Traditionally, either type of valve has beenimplanted using a surgical procedure that involves opening the patient'schest to access the mitral valve through the left atrium, and sewing thenew valve in position. This procedure is very invasive, carries risks ofinfection and other complications, and requires a lengthy period ofrecovery for the patient.

To simplify surgical procedures and reduce patient trauma, there hasbeen a recent increased interest in minimally invasive and percutaneousreplacement of cardiac valves. Replacement of a heart valve in this waytypically does not involve actual physical removal of the diseased orinjured heart valve. Rather, a replacement valve is delivered in acompressed condition to the valve site, where it is expanded to itsoperational state. One example of such a valve replacement systemincludes inserting a replacement pulmonary valve into a balloon catheterand delivering it percutaneously via the vascular system to the locationof a failed pulmonary valve. There, the replacement valve is expanded bya balloon to compress the native valve leaflets against the rightventricular outflow tract, thereby anchoring and sealing the replacementvalve. In the context of percutaneous, pulmonary valve replacement, U.S.Patent Application Publication Nos. 2003/0199971 A1 and 2003/0199963 A1,both filed by Tower, et al., describe a valved segment of bovine jugularvein, mounted within an expandable stent, for use as a replacementpulmonary valve. As described in the articles: “Percutaneous Insertionof the Pulmonary Valve,” Bonhoeffer, et al., Journal of the AmericanCollege of Cardiology 2002; 39: 1664-1669 and “Transcatheter Replacementof a Bovine Valve in Pulmonary Position,” Bonhoeffer, et al.,Circulation 2000; 102: 813-816, the replacement pulmonary valve may beimplanted to replace native pulmonary valves or prosthetic pulmonaryvalves located in valved conduits. Other implantables and implantdelivery devices also are disclosed in published U.S. Patent ApplicationPublication No. 2003/0036791 A1 and European Patent Application No. 1057 460-A1.

Due to the different physical characteristics of the mitral valve ascompared to the pulmonary valve, percutaneous implantation of a valve inthe mitral position has its own unique requirements for valvereplacement. There is a continued desire to be able to be able toimprove mitral valve replacement devices and procedures to accommodatethe physical structure of the heart without causing undue stress duringoperation of the heart, such as providing devices and methods forreplacing the mitral valve percutaneously.

SUMMARY

One embodiment of the invention includes a pericardial valve withartificial chords or chordae tendinae that closely replicates the nativeatrioventricular valve anatomy. This is accomplished by constructing avalve of two or more leaflets made of pericardium or other materialhaving a relatively thin profile at the annulus. The artificial chordaecan be constructed of ePTFE, for example, and can be attached in avariety of manners to the leaflets. These chords are positioned to mimicthe native valve anatomy and functionality. In particular, the valves ofone exemplary embodiment of the invention are sized to replace a mitralvalve and therefore the chords are arranged to prevent prolapse of theleaflets into the atrium.

The pericardial valve design of the invention advantageously provides astented valve having a relatively short height at its annulus due to thepositioning of the chords. In addition, the stented valves are capableof being crimped to a small enough size that they can be delivered tothe implantation site via transcatheter delivery systems and methods.

The stents used for the stented valves of the invention can becompressible and expandable stents for implantation into a body lumen,such as for replacement of one of the atrioventricular valves. The stentof one embodiment of these stented valves comprises a frame having acentral annular region, atrial flares extending from one side of theannular region, and ventricular flares extending from one portion of theopposite side of the annular region.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further explained with reference to theappended Figures, wherein like structure is referred to by like numeralsthroughout the several views, and wherein:

FIGS. 1 and 2 are top schematic views of a bi-leaflet and a tri-leaflettissue valve of the invention, respectively, and including multiplechord placement locations;

FIG. 3 is an oblique view of the tissue valve of FIG. 1 and illustratingmultiple anterior chords;

FIG. 4 is an oblique view of the tissue valve of FIG. 1 and illustratingmultiple posterior chords;

FIG. 5 is a schematic partial cross-sectional view of a tissue valve ofthe type illustrated in FIGS. 3 and 4 as positioned within a stentframe;

FIG. 6 is a front schematic view of an exemplary stent of the type thatcan be used with the tissue valves of the invention;

FIG. 7 is an oblique view of a portion of a tissue valve with attachedchords;

FIG. 8 is a cross-sectional side view of a portion of a tissue valve andillustrating exemplary chord attachment configurations;

FIG. 9 is a top schematic view of another valve arrangement of theinvention;

FIG. 10 is a schematic sectional view of a portion of a heart with astent frame of the invention positioned within the annulus of a mitralvalve;

FIG. 11 is a top schematic view of one exemplary leaflet of anothervalve arrangement of the invention;

FIG. 12 is a top view of another valve arrangement of the invention,with the leaflets in their closed position; and

FIG. 13 is a top view of the valve arrangement of FIG. 12, with theleaflets in their open position.

DETAILED DESCRIPTION

Referring now to the Figures, wherein the components are labeled withlike numerals throughout the several Figures, and initially to FIGS.1-5, a variety of views of one exemplary embodiment of a stented valve10 in accordance with the invention is illustrated. Although the stentedvalves of the invention, such as stented valve 10, are primarilydescribed herein as being used for mitral valve replacement, it isunderstood that many of the features of these stented valves can be usedfor valves in other areas of the heart. For example, the stented valvesof the invention may be used for replacement of the tricuspid valve,where the configuration of such a stented valve may be identical orslightly different than described herein for replacement of the mitralvalve due to the different anatomy in that area of the heart. In anycase, the stents and valves of the invention desirably restore normalfunctioning of a cardiac valve, and are intended for percutaneousimplantation to take advantage of the benefits of this type of surgery.However, the stents described herein may instead be implanted usingsurgical techniques that include minimally invasive methods or moretraditional open-heart surgical methods.

Stented valves of the invention, such as stented valve 10, comprise astent or stent frame and a valve comprising at least one leaflet that isattached within the interior portion of the stent frame using a varietyof different stent attachment devices and methods. Exemplary embodimentsof the stent frames of the invention are shown and described relative tothe figures, such as exemplary stent frame 12. The stent frames used forthe stented valves described herein may be fabricated of platinum,stainless steel, Nitinol, superelastic polymers (which in turn could bea shape memory polymer), or other biocompatible metals or combinationsof metals. The stent frames may alternatively be fabricated using wirestock, or may be produced by machining or laser cutting the stent from ametal tube, as is commonly employed in the manufacturing of stents. Thenumber of wires, the positioning of such wires, and various otherfeatures of the stent can vary considerably from that shown in thefigures, while remaining within the scope of the invention.

In any case, the stent frames of the invention are preferablycompressible to a relatively small diameter for insertion into apatient, but are also at least slightly expandable from this compressedcondition to a larger diameter when in a desired position in thepatient. It is further preferable that the process of compressing thestent frames does not permanently deform them in such a way that futureexpansion thereof would be difficult or impossible. That is, each stentshould be capable of maintaining a desired structural integrity afterbeing compressed and expanded. In one preferred embodiment of theinvention, the wires that make up each of the stent frames can be formedfrom a shape memory material, such as a nickel titanium alloy (e.g.,Nitinol). With this material, the stent frame can be self-expandablefrom a contracted state to an expanded state, such as by the applicationof heat, energy, or the like, or by the removal of external forces(e.g., compressive forces). Alternatively, the stent frame can be madeof materials that are expandable via expansion of a balloon or otherdevice that causes the stent frame to move from a compressed conditionto an expanded condition. The stent frame should be repeatedlycompressible and expandable without damaging the structure of the stentframe. In addition, the stent frame may be laser cut from a single pieceof material, as mentioned above, or may be assembled from a number ofdifferent components or wires. For these types of stent structures, oneexample of a delivery system that can be used includes a catheter with aretractable sheath that covers the stent and its associated valvestructure until it is to be deployed, at which point the sheath can beretracted to allow the stent frame to expand. Further details of such adelivery process for delivering stented valves of the present inventionare discussed in further detail below.

The stented valves described herein comprise one or more valve materialsattached within the inner area of the stent frame to form leaflets.These stented valve assemblies of the invention may use pericardialvalve material provided in a tricuspid or bicuspid leafletconfiguration. These configurations provide additional valve strength inthe relatively high-pressure conditions that exist in the mitral valvearea of the heart, and can also allow greater flexibility in designing avalve with a particular size and/or shape.

Referring again to FIGS. 1-5, a stented pericardial valve 10 isprovided, which is designed to mimic the native anatomy of theatrioventricular cardiac valves. This valve 10 is different from otherventriculo-arterial valves (i.e., semi-lunar valves) in that it dependson tendinous chords 30 (chordae tendinae) to anchor the leaflets to astent frame and prevent the prolapse of leaflets into the atrium. Inthis way, the stented valve 10 can advantageously have a relativelyshort annular height. This can be particularly beneficial fortranscatheter valves, as this relatively short annulus height provides astent that is able to be crimped to a relatively small size, and moreclosely replicates the function of the native mitral valve. In addition,the small annular height is advantageous for positioning of the valve,as it will fit more tightly around the native valve annulus, therebyforming a better seal. This concept can be used for either bi-leafletvalves, as is illustrated in FIGS. 1 and 3-5, or for tri-leaflet valves,as is illustrated in FIG. 4. In either case, the valve structuresinclude multiple chords 30 attached to or through the surface of thevalve leaflets. The artificial chords can be made of ePTFE, for example,and are attached to the surface of the leaflets to prevent prolapse ofthe leaflets into the atrium.

As is best illustrated in FIG. 5, stented valve 10 generally includes astent or stent frame 12 and a valve 14 attached within the interiorportion of the stent 12. The stent frame 12 generally includes anannular portion 16, an atrial portion 18 extending from one end of theannular portion 16, and a ventricular portion 20 extending from theopposite end of the annular portion 16. Atrial portion 18 includes awire structure that is shaped to flare or extend radially outward at anangle around the periphery of one end of the annular portion 16. Theatrial portion 18 is provided for engagement with one side of theannulus in which the stent frame 12 will be implanted, thus, the atrialportion 18 can be designed with a number of different configurations tomeet the different requirements of the locations in which it may beimplanted. Ventricular portion 20 also includes a structure that flaresor extends radially outward at an angle relative to the annular portion16. A section of this ventricular portion 20 can be specifically flaredrelative to the annular portion 16 in order to engage with the aorticleaflet (i.e., the aortic portion of the ventricular flare) but stillnot substantially block the left ventricular outflow tract. Theventricular portion 20 is provided for particular engagement with anannulus in which the stent frame will be implanted, such as theposterior side of a mitral annulus; however, it should not obstruct theleft ventricular outflow tract when implanted in the mitral position.

The stent frame 12 may include a number of wires or wire portions thatare attached to each other generally as shown in the illustratedconfiguration, where one arrangement could include separate wires foreach of the annular portion 16, the atrial portion 18, and theventricular portion 20. Alternatively, the entire stent frame 12 may becut from a single sheet of material such that the stent frame 12 is anintegral structure that does not include individual components. Therelative sizes and number of wire peaks, valleys, and flangesillustrated for each of the portions of the stent frame 12 areexemplary, and the construction can instead include different sizes,numbers, and configurations of these components.

When the stented valve is being provided for replacement of the mitralvalve, it is typically provided in an elliptical or oval shape, as isillustrated in FIGS. 1-4. In particular, FIGS. 1, 3, and 4 illustrate anexemplary bi-leaflet valve 14 which comprises an anterior leaflet 22 anda posterior leaflet 24. The leaflets 22, 24 can be constructed ofpericardium material with a relatively thin profile at the annulus. Inthe atrial view of a bi-leaflet valve of FIG. 1 and the atrial view of atri-leaflet valve of FIG. 2, multiple chord placements are illustratedas “X” markings on the leaflets, where the number of chords can besmaller or larger than illustrated. The chords can alternatively oradditionally be attached to the edge of the leaflet as well as the body.FIG. 3 illustrates chords 30 extending from the anterior leaflet 22 andFIG. 4 illustrates chords 30 extending from the posterior leaflet 24.FIG. 5 illustrates chords 30 of such a bi-leaflet valve 14 attached tostent frame 12, with the chords 30 attached to both the leaflets of thevalve and the ventricular portion 20 of the stent frame 12. In thisillustrated embodiment, the ends of the chords are attached at a pointof the ventricular portion furthest from the annular portion, however,it is understood that the chords can instead be attached at differentlocations on the stent frame. The chords may also be attached at one ormore levels of the ventricular flares.

Attachment of the multiple chords 30 to the surface of the leaflets canbe performed in a number of different types of ways, where a particularstented valve can use one or more different types of attachment methodsand/or devices. One attachment method is generally illustrated in FIGS.3 and 4, in which each chord 30 is passed through the leaflet materialin two locations that are at closely adjacent to one another so thatboth ends of the chord are on the same side of the leaflet and arrangedas a pair. When attaching the ends of these chords to a stent frame,each end of the pair can be attached independently to the stent frame atlocations that are spaced at least somewhat from each other, or the pairof chord ends can be treated as a single unit and kept together as apair when being attached to the stent frame.

Another attachment method is illustrated in FIG. 7, which shows a chord32 entering a leaflet material at a location 34, extending across theopposite side of the leaflet by a distance (shown as a broken line), andthen exiting the leaflet material at a location 36. Such a separation ofthe ends of the chord in this way can distribute the forces and help toprevent possible tearing or ripping of the leaflet material.

Additional attachment methods are illustrated for attaching chords to aleaflet portion 40 in FIG. 8. Leaflet portion 40 includes a firstsurface 50 and an opposite surface 52. Chord 42 is shown as having oneend attached to a piece of material or tab 44 that is positioned againstthe second surface 52 of the leaflet portion 40. The chord 42 thenpasses through the leaflet 40, extends across a portion of the firstsurface 50, then passes back through the leaflet so that its free endextends from the second surface 52. Similarly, chord 46 has one endattached to a piece of material or tab 48 that is positioned against thefirst surface 50 of the leaflet portion 40. The chord 46 passes throughthe leaflet 40 so that its free end extends from the second surface 52.A single leaflet may comprise one or both of these chord attachmentconfigurations, or may comprise one or a combination of different chordattachment configurations.

In other alternative arrangements, chords can be attached to leaflets ofa valve using sutures, adhesives (e.g., bioadhesives), tissue welding,and the like. The chords may be provided as single structures or may beprovided in pairs or larger groupings. The chords may also be providedwith different lengths to accommodate certain desired distances betweenthe portion of the leaflet to which they are attached when the valve isin its closed configuration and the stent frame to which the chords areattached. The chords may further be provided with the ability to beadjusted in length, if desired, in order to optimize the performance ofthe valve, for example.

The chords themselves may be made of a wide variety of materials, whichcan generally fall into the broad categories of: (1) synthetic ormanufactured chords; and (2) harvested or native chords. In either case,the chords should be selected to have certain properties that aredesirable and/or necessary for the particular valve in which they willbe used. For one example, the chord material can be selected to providechords that are not subject to fatigue failure, even after very highnumbers of cycles under which the chords will be subjected to relativelyhigh stresses. In addition, the chord material can be selected frommaterials that will not stretch, as the performance of the stented valvewill significantly suffer if the chords can stretch or extend far enoughthat the leaflets will be able to prolapse into the atrium, for example.Examples of materials from which the chords can be made include silk andultra high molecular weight polyethylene.

The chord material can further be selected to be compatible with thematerial from which the leaflets are made. As described above, theleaflets may be made of pericardial material; however, the leaflets mayinstead be made of another material, such as native leaflets obtainedfrom a donor source (e.g., leaflets from a porcine valve), leaflets madefrom other membranous tissue in the body, such as intestinal submucosa,thin film Nitinol, cloth, or a polymeric material, for example. Onepolymeric material from which the leaflets can be made is an ultra highmolecular weight polyethylene material commercially available under thetrade designation “Dyneema” from Royal DSM of the Netherlands. Withcertain leaflet materials, it may be desirable to coat one or both sidesof the leaflet with a material that will prevent or minimize overgrowth.It is further desirable that the leaflet material is durable and notsubject to stretching, deforming, or fatigue.

The stented valves of the invention may alternatively be provided with avalve having three or more leaflets, where an exemplary tri-leafletvalve 15 is illustrated in FIG. 2. All of the features and variationsdescribed above relative to bi-leaflet valves are also applicable foruse with tri-leaflet valves or with valves having more than threeleaflets. For example, the valve 15 has three leaflets 26 that areattached along one edge to a stent frame that can be oval or ellipticalin shape, for example. Each of the leaflets 26 includes multiple chordsextending from their surfaces, where each of the chord placements isillustrated as an “X” marking on the leaflets. Any of the describedchord attachment methods described above can also be used for attachmentof these chords to the leaflets 26 of the tri-leaflet valve 15.

FIG. 9 is a top schematic view of a stented valve 80 that includes asingle piece of leaflet material 82. The leaflet piece 82 is stitched toa stent frame along an edge 84, thereby creating a fixed leaflet portion92 and a moveable leaflet portion 94. Leaflet portion 94 can moverelative to fixed portion 92 along fold line 86, where its free edgecloses against a stent edge 88. In order to keep the leaflet portion 94from prolapsing or moving too far into a vessel, leaflet portion 94 canhave multiple chords attached to it using any of the materials andtechniques described above, such as at the locations 90 designated by an“X” in the figure.

FIG. 11 illustrates a leaflet piece 100 that includes another chordattachment arrangement for use with a stent frame. In particular,leaflet piece 100 includes a base portion 102 and multiple chord orattachment portions 104 that are formed by cutting leaflet piece 100along cut lines 106. In use, the base portion 102 is attached to a stentframe along an attachment edge 110 and the chord portions 104 can befolded downward generally along a fold line 108. The free ends 112 ofthe chord portions 104 are attachable to a lower portion of a stentframe (e.g., a ventricular portion of a frame) to function to preventleaflet prolapse, in accordance with the invention.

FIGS. 12 and 13 illustrate another valve embodiment 120 that comprisesan anterior leaflet 122 and a posterior leaflet 124 that are attached toa stent frame. In this embodiment, posterior leaflet 124 has two gaps oropenings along one edge that allow for a more flexible movement of theleaflet 124 during opening and closing of the valve. FIG. 12 shows theleaflets in a closed position and FIG. 13 shows the leaflets in an openposition. These Figures illustrate the changes that take place in thestent shape and size during a cardiac cycle. In particular, duringfilling, the stent will be at its largest shape and the gaps will beopen, as is illustrated in FIG. 13 with open gaps 128, an open area 132,and a broken line 130 that generally shows the intersection line of theleaflets when the valve is in its closed position. During systole andventricular ejection, the stent or supporting structure will deform andpotentially become smaller. These gaps will then close, as isillustrated with the closed gap areas 126 of FIG. 12. The gaps thusprovide more flexibility to the leaflet during valve movement, whichallows the leaflets to coapt more effectively and reduces leakage. Inother words, the gaps in the posterior leaflet 124 help to provide avalve that more closely mimics the natural mitral valve morphology andfunction.

The stented valves of the invention can further include a coveringmaterial that is attached to selected wires of the stent frame, and maybe attached to all of the wires or wire portions of stent frame, ifdesired. The covering material can be a knit or woven polyester, such asa polyester or PTFE knit, which can be utilized when it is desired toprovide a medium for tissue ingrowth and the ability for the fabric tostretch to conform to a curved surface. Polyester velour fabrics mayalternatively be used, such as when it is desired to provide a mediumfor tissue ingrowth on one side and a smooth surface on the other side.These and other appropriate cardiovascular fabrics are commerciallyavailable from Bard Peripheral Vascular, Inc. of Tempe, Ariz., forexample. The covering material could also be a natural material such aspericardium or another membranous tissue such as intestinal submucosa.The covering material can be the same material or different than thematerial from which the leaflets are made. The covering material may beattached to its respective stent frame by sewing, adhesives, or otherattachment methods.

FIG. 10 illustrates a portion of a heart 140, with an exemplary stentassembly 141 of the invention positioned therein. In particular, heart140 includes a left atrium 142, a left ventricle 144, a mitral valvespace 146 and an aortic valve 148. When the native mitral valve isoperating properly, the native leaflets will generally function in sucha way that blood flows toward the left ventricle 144 when the leafletsare in an open position, and so that blood is prevented from movingtoward the left atrium 142 when the leaflets are in a closed position.However, stent assembly 141 can be positioned in the area of mitralvalve 146 when it is not functioning properly (to replace the mitralvalve) in accordance with the invention, thereby pushing the leafletsout of the mitral valve space, such as are shown as leaflets 156 and158, respectively.

As shown, stent assembly 141 includes an annular portion 160, an atrialportion 162 extending from one side of the annular portion 160 andtoward the left atrium 142, and a ventricular portion 164 extending fromthe posterior side of the annular portion 160 and toward the leftventricle 144. The stent assembly 141 further includes multiple chords180, each of which is attached at one end to leaflets 184 and attachedat their other end to the stent frame 141. The stent assembly 142 willpreferably be configured so that it does not push the leaflet 156 to aposition in which it will interfere with blood flow through the aorticvalve 148 and/or interfere with the actual movement or functioning ofthe leaflets of the aortic valve 148. However, annular portion 160preferably has a sufficient length to provide a suitable area of contactwith the annulus of the mitral valve to help to maintain it in itsdesired position.

As stated above, the stent assemblies of the invention can also beimplanted for replacement of the tricuspid valve. In particular, if thestent assemblies of the invention are positioned within the annulus of atriscuspid valve, the atrial portion would be configured in such as waythat it would not contact the apex of the triangle of Koch in order tonot disturb the conduction system (i.e., the AV node and bundle of His).In addition, the ventricular portion would be configured so that it doesnot contact the septal portion of the ventricle in order to not disturbthe conduction system, wherein these atrial and ventricular portions canthus be similar to those described above relative to stent assembliesfor the mitral area.

Stent frames of the type described above can be assembled into a stentedvalve assembly in accordance with the methods of the invention describedherein, although such valves are not shown in the Figures. One exemplarymethod for assembling a stented valve generally first includespreparation of a pericardial material, then a subsequent mounting orattachment of the pericardial material to the stent frame using avariety of mounting or attachment techniques. Bi-leaflet, tri-leaflet,and other variations of valve assemblies can be attached within thestent frames described herein.

The various flared portions described above relative to the atrialportions and ventricular portions of the stent frames are generallyshown (e.g., in FIG. 6) as being V-shaped or U-shaped. However, theflared portions may instead be semi-circular, rectangular, oblong, orthe like, and may be considerably smaller or larger than shown. In yetanother variation, a different flare structure that is more continuousaround the periphery of the annular portion of the stent frame can beused (i.e., the flare structure does not comprise a series of adjacentflares but instead comprises more of a continuous flared structure atone or both ends of the stent frame). In any case, the flare portion(s)are preferably configured to be a shape and size that can provide ananchoring function for the stent assembly when it is positioned toreplace a valve. For example, if stent assembly were positioned withinthe mitral valve annulus any flare portions that extend from the stentassembly on the atrial side can provide interference with the walls ofthe left atrium, thereby inhibiting motion of the stem assembly.

Any of the embodiments of stent assemblies described herein relative tothe invention, may include a gasket or other member around its exteriorto provide for sealing against paravalvular leakage and to facilitatepannus in-growth for stabilization of the stent. Such a gasket or othermember may alternatively or additionally be positioned on the interiorportion of the stent or on the underside of a cuff provided on thestent.

In addition, it is contemplated that the ventricular flares associatedwith the stented valves of the invention can house biologics to targetinfarcts (stem cells, genes, proteins, etc.), which are often locatedposterior-inferiorly in patients with ischemic mitral regurgitation. Theareas of the stented valves of the invention used for anchoring couldalso be seeded with cells or biologics to promote ingrowth for quickincorporation into the surrounding tissue. This could aid in eliminatingparavalvular leakage and in eliminating migration or embolization of theprosthesis. In one example for a mitral valve replacement, the atrialand annular portions can include pro-ingrowth biologics and theventricular portion can include therapeutic biologics and/orpro-ingrowth biologics.

The stent assemblies of the present invention may be positioned withinthe desired area of the heart via entry in a number of differentmethods. In one example, the stent assembly may be insertedtransatrially, where entry may be done either percutaneously or in aminimally invasive technique on a beating heart in which access isthrough the side of the heart, or even through a standard open heartvalve replacement procedure using heart-lung bypass and sternotomy wherethe described device would be used as an alternative to the standardreplacement. In another example, the stent assembly may be insertedtransapically, where entry again may be done either percutaneously or ina minimally invasive technique on a beating heart in which access isthrough the side of the heart. In yet another example, the stentassembly may be inserted transeptally, where entry can be donepercutaneously. In yet another example, the stent assembly is deliveredusing an antegrade approach in which the ventricular portion of thestent is unsheathed and allowed to expand first, and then positioned atthe annulus before releasing the atrial portion of the stent.

The invention further includes a method of positioning a valve into abody lumen, such as one of the atrioventricular valve openings of theheart. The method comprises the steps of compressing a stent frame of astented valve, wherein the stent frame includes a central annularregion, an atrial portion, and a ventricular portion. A sheath or othercomponent of a delivery system can be slid or otherwise positioned overthe compressed stented valve to keep it from expanding and to minimizeinterference between the stented valve and the vasculature through whichit will be traveling. The stented valve is then delivered to the annulusof the desired valve area of the patient, which delivery may beperformed transapically, for example. In one method, the valve isaccessed through the bottom of the valve. When the valve is in position,the atrial region or portion of the stent is released, such as byretracting the sheath of the delivery system by a sufficient amount thatthis portion of the stented valve is exposed. Due to the self-expandingproperties of the stent frame, this atrial portion will expand outwardlyrelative to the sheath in which it was enclosed. The delivery system isthen used to pull the stent valve back against the annulus to engage theatrial portion of the stent with the annulus. The sheath of the deliverysystem can then be further retracted to release the ventricular portionof the stent frame from the delivery system. Due to the self-expandingproperties of the stent frame, this ventricular portion will expandoutwardly relative to the sheath in which it was enclosed. The deliverysystem can then be retracted from the patient.

The present invention has now been described with reference to severalembodiments thereof. The contents of any patents or patent applicationcited herein are incorporated by reference in their entireties. Theforegoing detailed description and examples have been given for clarityof understanding only. No unnecessary limitations are to be understoodtherefrom. It will be apparent to those skilled in the art that manychanges can be made in the embodiments described without departing fromthe scope of the invention. Thus, the scope of the present inventionshould not be limited to the structures described herein.

What is claimed is:
 1. A stented valve comprising: a stent frame comprising first and second end portions extending from an annular portion, wherein the first end portion is flared radially outwardly relative to the annular portion; a prosthetic valve comprising first and second leaflets attached within an interior area of the annular portion, the first and second leaflets each comprising a body portion between a fixed leaflet edge portion and a free edge, the first and second leaflets being movable between an open position and a closed position, the first leaflet and the second leaflet coapting at the closed position; and a first chord attached to the body portion of the first leaflet and the first end portion of the stent frame, the first chord being arranged to prevent prolapse of the first leaflet.
 2. The stented valve of claim 1, further comprising a second chord attached to the body portion of the second leaflet and the first end portion of the stent frame, the second chord being arranged to prevent prolapse of the second leaflet.
 3. The stented valve of claim 2, wherein the prosthetic valve further comprises a third leaflet attached within the interior area of the annular portion, the third leaflet being movable between the open position and the closed position, the third leaflet coapting with the first leaflet and the second leaflet at the closed position; and a third chord attached to a body portion of the third leaflet and the first end portion of the stent frame, the third chord being arranged to prevent prolapse of the third leaflet.
 4. The stented valve of claim 1, wherein the first chord is adhered to the first leaflet.
 5. The stented valve of claim 1, wherein a first end and a second end of the first chord extend from the same side of the first leaflet.
 6. The stented valve of claim 5, wherein the first and second ends of the first chord are attached to the first end portion of the stent frame.
 7. The stented valve of claim 1, wherein the first chord extends from a first side of the first leaflet to a second side of the first leaflet.
 8. The stented valve of claim 1, wherein the first leaflet and second leaflet comprise pericardial material.
 9. The stented valve of claim 1, wherein the first chord comprises a synthetic material.
 10. The stented valve of claim 1, wherein the stent frame is compressible and expandable for percutaneous delivery and implantation into a body lumen.
 11. The stented valve of claim 1, wherein the stent frame comprises a shape memory material.
 12. The stented valve of claim 1, further comprising a covering material attached to at least a portion of the annular portion.
 13. The stented valve of claim 1, wherein the first chord comprises a first end attached to a tab member, wherein the tab member is adjacent to a first surface of the first leaflet.
 14. The stented valve of claim 1, wherein the second end portion flares radially outward relative to the annular portion.
 15. The stented valve of claim 1, wherein the first chord passes through the body portion of the first leaflet at two locations closely adjacent to each other. 